Hi Max,
You can edit the layout of the property details page in : components > com_osproperty > templates > default > details.html.tpl.php or components > com_osproperty > templates > default > small.details.html.tpl.php
You also need to edit the function
propertyDetails() in file components > com_osproperty > classes > listing.html.php
If you need more support from me, please add my Skype name : thucdam84. I will happy to support to you.
Thanks
Dam